1. Field of the Invention
The present invention relates to a hermetically sealed barrier closure for a container that can provide a liquid-tight reseal after the hermetic seal is broken.
2. Description of Related Art
Tubes and containers include an open top having a closure that can be removed or opened to access the interior of the container.
Some closures comprise an elastomeric stopper that can be urged into the open top of the container to provide a liquid-tight seal. The stopper can be removed to access the interior of the container and then can be replaced in the opening to reseal the container. The stopper provides a liquid-tight seal both before the initial opening of the container and during any reclosure of the container. However, stoppers do not provide a hermetic seal which is necessary in some instances to ensure sterility.
Other closures include structure for threaded or snap-fit engagement with the top of the container. These closures are convenient for periodically accessing the contents of the container, but may not provide an adequate liquid-tight seal, and do not provide a hermetic seal.
Some containers have a barrier bonded or hermetically sealed over the open top of the container. The barrier is substantially impermeable to most gases and liquids, and hence, the contents of the container can be hermetically sealed prior to use. However, these barriers cannot reseal the open top to the container after the initial opening. Thus, an entirely separate closure is required to reclose the container after the initial use.
The present invention is directed to a resealable barrier closure for a container. The container includes a closed bottom, an open top and a continuous side wall extending therebetween. An annular snap ring or other engagement structure may project outwardly from the side wall at a location spaced slightly from the open top of the container.
The resealable barrier closure includes a shell with a top wall that generally conforms to the shape of the open top of the container. The top wall of the shell may include an aperture extending therethrough for accommodating a needle cannula that may be used to deposit material into the container or to withdraw material from the container.
The shell of the resealable barrier closure further includes an outer skirt that is dimensioned to telescope over the open top of the container. Inner circumferential portions of the outer skirt may include a snap ring or other engagement structure for resealable engagement with the snap ring or other such engagement structure on the container.
The shell further includes an inner skirt projecting from the top wall and spaced circumferentially inwardly from the outer skirt. The inner skirt preferably defines an outside diameter approximately equal to the inside diameter of the opening to the container. Thus, the shell can be tightly fitted onto the open top of the container, with the inner skirt engaged against the inner surface of the container adjacent the open top and with the outer skirt engaged with the outer surface of the container adjacent the open top.
The resealable barrier closure further includes an elastomeric diaphragm that is resiliently engaged within the inner skirt of the shell. Thus, the elastomeric diaphragm biases the inner skirt outwardly and helps to achieve a liquid tight seal between the inner skirt and the inner surface of the container adjacent the open top.
The resealable barrier closure further includes a barrier for sealing the container. The barrier may be formed substantially into the shape of a cup, and thus may have a bottom wall and a side wall extending upwardly from the bottom wall. The bottom wall extends continuously across the bottom end of the inner skirt and across the bottom surface of the elastomeric diaphragm. The side wall of the barrier surrounds the inner skirt of the shell. The barrier may further include a top flange that extends outwardly from the side wall. The top flange lies adjacent the bottom surface of the top wall of the shell and extends substantially continuously between the inner and outer skirts.
The resealable barrier closure is mounted to the open top of the container such that the outer skirt telescopes around the open top and such that the inner skirt and portions of the barrier surrounding the inner skirt telescope into the open top. The closure is urged downwardly onto the container until the snap ring on the outer skirt engages the snap ring on the container. This complete seating of the closure with the container achieves intimate contact between the outer surface of the side wall of the barrier and the inner surface of the side wall of the container. Additionally, the top flange of the barrier achieves intimate contact with both the top edge of the container and the bottom surface of the top wall of the shell. This assembly may be heated so that the barrier is bonded to adjacent regions of the shell and the container to provide a hermetic seal.
The container may be opened by urging the closure upwardly relative to the top of the container. Forces on the closure cause the snap rings to disengage and cause the barrier to separate from the container. The container may be resealed by urging the closure downwardly until the snap ring of the shell engages the snap ring on the container. This snapped engagement ensures that the inner skirt is fully telescoped within the open top of the container. Resilient forces exerted by the elastomeric diaphragm urge the inner skirt and adjacent portions of the barrier seal into fluid-tight engagement with the container.